The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Various applications utilize parts with an axis of rotation and splines on shafts. For example, gear transmissions in motor vehicles often include a hypoid driving pinion to transmit power, or torque, to drive axles. Often, the surfaces of splined parts vary from their nominal dimensions due to manufacturing variation and wear. Measuring the actual variation of splined surfaces can be challenging. Generally, variation can be measured by “runout” and “total runout.”
Runout is how much a given reference feature or features vary with respect to another datum when a part is rotated 360° around a datum axis. Runout is typically a control for a circular feature and indicates how much radial variation the feature has about a rotational axis. Runout can be called out on any feature that is rotated about an axis.
Total runout is how much an entire feature or surface varies with respect to a datum when the part is rotated 360° around the datum axis. Total runout indicates both the amount of radial dimensional variation in the surface as the part is rotated and the amount of dimensional variation in the axial dimension. Both radial dimensional variation and axial dimensional variation are measured by total runout.
Because splined surfaces are not smooth, measuring runout and total runout can be challenging. The challenges of measuring dimensional variation of splined parts, among other types of parts, are addressed by the present disclosure.